A practical and versatile instrument has been developed both to
optimize the chemistry of bio- and chemiluminescence reactions and to
measure ultra-trace quantities of associated analytes. The instrument
consists of a pneumatic flow injection system linked to a detection cell and a
signal processing and readout system. The disk-like cell...
A fiber optic fluorometer utilizing a double-fiber optic probe
was constructed. The absolute fluorescence signal and effective
collection efficiency are approximately one fifth those of typical
cuvette fluorometers and agree with those predicted by theory. A
quinine sulfate calibration curve shows linearity from a detection
limit of 10 pg/mL to...
Two related techniques, based upon ion-exchange solid phase extraction, have been
developed for the determination of arsenic speciation. The inorganic arsenic species
arsenite (As(III)) and arsenate (As(V)) are separated by anion-exchange and detected with
graphite furnace atomic absorption spectrophotometry (GFAAS) with a nickel matrix
modifier. The first separation technique, which...
A procedure for evaluating the precision of atomic absorption
measurements is presented and applied to 21 elements under varying
instrumental conditions. The experimental relative standard deviations
(RSD's) in absorbance obtained from repetitive measurements made
with a high resolution voltmeter and on-line computer, are compared
to those predicted by a recently...